Perhaps you should try some spelling variations:
"world economic and financial studies." » "world economic and financial services."
"world economy and financial stress." » "world economy and financial distress.", "world economy and financial access.", "world economy and financial strength."
"world economic and financial series." » "world economic and financial services.", "world economic and financial service.", "world economic and financial systems."

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (("world economy and financial stress.") OR ((((("world economic and financial series.") OR ("world economic and financial barriers."))) OR ("world economic and financial studies."))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"world economy and financial stress.\") or (((((\"world economic and financial series.\") OR (\"world economic and financial barriers.\"))) or (\"world economic and financial studies.\"))))~".
• Removing quotes may allow a broader search: (( world economy and financial stress. ) or ((((( world economic and financial series. ) OR ( world economic and financial barriers. ))) or ( world economic and financial studies. ))))~.
• Adding a wildcard symbol may retrieve word variants: (("world economy and financial stress.") or ((((("world economic and financial series.") OR ("world economic and financial barriers."))) or ("world economic and financial studies."))))*.